TapSafetyReport
B75/100

CASTLE ROCK TOWN OF — Water Quality Report 2026

Serving 106,822 people · Colorado

Water Source
Surface Water
County
—
System ID
CO0118010
Violations
19

Contaminant Test Results

2 contaminants above EPA health goals
ContaminantDetectedLimit (MCL)Status
chlorate
340.00 µg/L—Above Goal
Lead (90th percentile)
0.002 mg/L0.015 mg/LAbove Goal

EPA Violation History

8

Violations (last 5yr)

0

Unresolved

0

Health-Related

TIER 3Resolved

Failed to complete routine monitoring

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: June 1, 2025 – June 30, 2025Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Failed to complete routine monitoring

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: May 1, 2025 – May 31, 2025Rule: Surface Water Treatment RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: April 1, 2022 – June 30, 2022Enforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: April 1, 2022 – June 30, 2022Enforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: April 1, 2022 – June 30, 2022Enforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: April 1, 2022 – June 30, 2022Enforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: April 1, 2022 – June 30, 2022Enforcement: Resolving — corrective action underway
TIER 3Resolved

Exceeded the MCL for disinfection byproducts

This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.

When: April 1, 2022 – June 30, 2022Enforcement: Resolving — corrective action underway

Understanding violation severity

Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.

Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly

Frequently Asked Questions About CASTLE ROCK TOWN OF

Is CASTLE ROCK TOWN OF water safe to drink?

CASTLE ROCK TOWN OF water receives a grade of B (75/100), which is considered good. Out of 69 contaminants tested, none exceed EPA legal limits. 2 contaminant(s) exceed non-enforceable health goals. The water meets federal safety standards.

What contaminants has CASTLE ROCK TOWN OF detected?

69 contaminants were tested in CASTLE ROCK TOWN OF's water. Notable contaminants include Lead (90th percentile), chlorate. No contaminants exceed EPA legal limits. 2 exceed EPA health goals (MCLGs).

Does CASTLE ROCK TOWN OF have any EPA violations?

Yes, CASTLE ROCK TOWN OF has 19 EPA violation(s) on record, with the most recent in 2025. Violation types include MR, Other.

How many people does CASTLE ROCK TOWN OF serve?

CASTLE ROCK TOWN OF serves approximately 106,822 people, Colorado.

What type of water does CASTLE ROCK TOWN OF provide?

CASTLE ROCK TOWN OF sources its water from surface water. Surface water comes from rivers, lakes, or reservoirs and typically requires more extensive treatment. The utility's system ID is CO0118010.

How does CASTLE ROCK TOWN OF compare to other utilities in Colorado?

CASTLE ROCK TOWN OF scores 75/100 with a grade of B (good). This is an above-average performance for utilities statewide. Visit our Colorado state page for a full comparison of water systems.